[BNM] CSS help

[Chris Billett]

So, I have a bit of a 'mare with a site that I'm knocking together. Err,
while I know HTML, CSS and a bit of PHP (and know Vanilla pretty well) I
cannot for love nor money figure out why the red 'WELCOME' block here causes
Internet Explorer 6 to go goofy:
http://www.hilldun.com/indextest.html

Compare the IE6 or IE5.5 rendering to Firefox or anything else, and it's
shocking. Nothing I can see should be breaking it, though.

Any tips? Feel free to tear the site and code to bits in any way you like -
it's in fairly early stages of development still so I can take a cussing.

CB